Two years ago, Facebook Inc. offered its in-house recruiters an incentive to help diversify its largely white, largely male workforce.

Previously, recruiters were awarded one point for every new hire. Under the new system, they could earn 1.5 points for a so-called “diversity hire”—a black, Hispanic or female engineer—according to people familiar with the matter. More points can lead to a stronger performance review for recruiters and, potentially, a larger bonus, the people said.

When the numbers didn’t move, Facebook sweetened the deal. Starting last year, recruiters earned two points for a minority hire, or twice as much as for white or Asian males, who already were well-represented within its technical ranks.

Even so, Facebook has shown little progress. Last month, the company said 4% of its U.S. employees were Hispanic and 2% were black, the same as the two prior years. Women made up 33% of its global workforce, up from 31% in 2014.

A Facebook spokeswoman declined to comment on the incentive and wouldn’t say if it is still in use. “We continue to experiment with a variety of approaches to help in our efforts to increase the diversity of our workforce,” she said.